🔐 Secure File Transfer - Enterprise Security Suite v3.4.01c34

A professional, secure file transfer application with enhanced network discovery, multi-antivirus security support, and enterprise-grade trusted device management. Features intelligent device naming, real-time network scanning, and a modern CustomTkinter interface with comprehensive security features.

✨ What's New in v3.4.01c34

🚀 Enhanced Network Discovery

• Smart Device Naming: Real hostname detection with intelligent fallbacks

  • DESKTOP-ABC123 - Your actual computer names when available
  • Main-Router - Primary network gateway (.1 addresses)
  • Workstation-114 - Desktop/laptop computers (100-150 range)
  • Infrastructure-41 - Network equipment (11-50 range)
  • Server-156 - Server devices (151-199 range)
  • Mobile-Device-201 - Mobile/IoT devices (200-254 range)

• Multi-Method Discovery:

  • DNS Reverse Lookup: Finds real computer names like "DESKTOP-ABC123"
  • NetBIOS Queries: Windows computer name resolution
  • ARP Table Scanning: Pre-discovery of active devices
  • Port Detection: Smart device classification by open services
  • Ping + Port Scanning: Combined reachability testing

• Optimized Performance:

  • 500ms timeouts for DNS/NetBIOS (balanced speed vs accuracy)
  • No hanging during network scans
  • Intelligent caching of discovered devices
  • Real-time updates as devices come online

🛡️ Multi-Antivirus Protection

• ESET Integration: Primary security service with enhanced protection
• Kaspersky Support: Full compatibility and real-time protection
• Norton Security: Complete enterprise security integration
• Windows Defender: Built-in Windows protection support
• Bitdefender: Professional antivirus integration
• Avast/AVG: Consumer antivirus support
• McAfee: Enterprise security compatibility
• Auto-Detection: Automatically detects your security software

🤖 Smart Auto-Discovery

• Background Scanning: Continuously finds new devices on your network
• Auto-Trust Patterns: Automatically trusts devices matching your rules
• Smart Caching: Remembers devices to reduce network load
• Real-time Updates: Live device status and connection monitoring
• Configurable Intervals: Set scan intervals from 10 seconds to 5 minutes

🔐 Advanced Security Features

• Zero-Trust Model: All devices start as "Untrusted" by default
• Trust Levels: Limited, Standard, and High security levels
• Device Certificates: Automatic certificate generation with expiration
• Fernet Encryption: Industry-standard encryption for all transfers
• Input Validation: Comprehensive protection against malicious inputs
• File Integrity: MD5 hash verification for all file transfers

📁 Universal File Support

• All File Types: Transfer any file format without restrictions (.exe, .pdf, .mp4, etc.)
• Large File Support: Configurable file size limits up to GB scale (default: 2GB)
• Smart Validation: Automatic file size checking with clear error messages
• Flexible Limits: Easily adjust maximum file sizes through configuration
• Type Categories: Helpful file type suggestions in selection dialog

📱 Modern User Interface

• Dark Theme: Professional CustomTkinter interface
• Tabbed Design: Send, Receive, Trusted Devices, and Security tabs
• Real-time Device List: Live updates of network devices with meaningful names
• Progress Tracking: Real-time progress bars and status updates
• Responsive Design: Works on different screen sizes

🔍 How Network Discovery Works

Device Detection Process

1. ARP Table Scan: Quickly finds active devices from system ARP cache
2. Reachability Test: Ping + port scan to confirm device availability
3. Name Resolution: Multi-method hostname discovery
4. Service Detection: Check for file transfer service on port 12345
5. Smart Classification: Categorize device based on IP and discovered services

Device Naming Intelligence

192.168.1.1   → Main-Router        (Primary gateway)
192.168.1.2   → Secondary-Router  (Secondary gateway) 
192.168.1.41  → Infrastructure-41  (Network equipment)
192.168.1.103 → DESKTOP-ABC123    (Real computer name found)
192.168.1.114 → Workstation-114   (Desktop computer)
192.168.1.156 → Server-156        (Server device)
192.168.1.201 → Mobile-Device-201 (Mobile/IoT device)

Note: The application automatically detects your network range:

• 192.168.1.x (most common home networks)
• 192.168.0.x (alternative home networks)
• 10.0.0.x (some routers and corporate networks)
• 172.16.x.x (corporate networks)

Trust Status Explained

• 🔴 Untrusted: Device discovered but not approved (security default)
• ✅ Trusted: Device manually approved or auto-trusted by patterns
• 🟢 Available: Device is trusted and ready for file transfers
• ⚠️ No Service: Device found but not running file transfer service

🚀 Getting Started

🔧 System Requirements

• Operating System: Windows 10/11, macOS 10.14+, or Linux
• Python: 3.11+
• Memory: 100MB RAM minimum
• Storage: Less than 50MB disk space
• Network: Local network access (WiFi or Ethernet)

📦 Installation

1. Download the application files to your computer
2. Install Python dependencies:

   pip install customtkinter cryptography psutil pyarmor

3. Run the application:
   • Recommended: python launchers/launcher.py
   • Direct: python src/file_transfer_app.py

⚙️ Configuration

The application uses config/config.json for settings:

{
  "app_settings": {
    "version": "3.4.01c34",
    "max_file_size_gb": 2,
    "port": 12345,
    "scan_timeout": 30
  }
}

🎯 First Time Setup

1. Launch the application using python launchers/launcher.py
2. Scan Network - Click "🔍 Scan Network" to discover devices
3. Review Devices - See discovered devices with intelligent names
4. Trust Devices - Click "✅ Trust" on devices you want to allow
5. Start Transferring - Send/receive files securely!

🖥️ IMPORTANT: Multi-Device Setup Required

⚠️ Key Requirement: To transfer files between devices, you must install and run this application on ALL devices you want to include in your secure network.

Example Setup:

• Device A: Install app → Trust Device B → Send files to Device B
• Device B: Install app → Trust Device A → Receive files from Device A
• Both devices: Must be on the same network and trust each other

Why needed: Each device runs its own secure file service. Without the app installed, devices cannot send or receive encrypted files.

📖 How to Use

📤 Sending Files (Complete Guide)

1. 📂 Select Your Files

   • Click "🗂️ Select Files" button in the Send tab
   • Choose one or more files (ALL file types supported: .exe, .pdf, .mp4, .zip, etc.)
   • Files appear in the list with their sizes
   • Maximum: 2GB per file (configurable in config.json)

2. 🔍 Discover Network Devices

   • Click "🔍 Scan Network" to find devices
   • Wait 10-30 seconds for comprehensive scan
   • Devices appear with intelligent names:
     • Real names like "OFFICE-LAPTOP" (when discoverable)
     • Smart fallbacks like "Workstation-114", "Main-Router"
   • Status shows: Available, Untrusted, or No Service

3. 🛡️ Trust Devices (Security Step)

   • Untrusted devices: Click "✅ Trust" to approve them
   • Only trusted devices can send/receive files (zero-trust security)
   • Trusted devices show green indicators
   • View certificates and trust levels in "Trusted Devices" tab

4. 🎯 Select Target Device

   • Click "🎯 Select" on your target device
   • Device highlights in green when selected
   • Must be a trusted device with file service running

5. 📤 Transfer Files

   • Click "📤 Send Files" to start transfer
   • Watch progress bar and status updates
   • Files are encrypted during transfer
   • Completion notification appears

📥 Receiving Files (Complete Guide)

1. 📂 Set Download Location

   • Default: Your Downloads folder
   • Click "📁 Browse" to choose different location
   • Ensure sufficient disk space available

2. 🟢 Start File Service

   • Click "🟢 Start Receiver" in Receive tab
   • Status changes to "🟢 Running - Ready to receive files"
   • Your device now accepts incoming transfers
   • Other devices will see you as "Available"

3. 📋 Monitor Transfers

   • Watch transfer log for incoming files
   • Real-time progress updates
   • Files automatically appear in download location
   • All transfers logged with timestamps and source

4. 🔧 Manage Service

   • Click "🔴 Stop Receiver" when done
   • Service stops automatically on app close
   • Can change download folder anytime

🔧 Network Management

1. 🔍 Device Discovery

   • Manual Scan: Click "🔍 Scan Network" anytime
   • Auto-Scan: Enable in Security tab for continuous discovery
   • Scan Range: Automatically detects your network (10.0.0.x, 192.168.x.x, etc.)
   • Multi-Method: Uses DNS, NetBIOS, ARP, and ping for comprehensive discovery

2. 🛡️ Device Security

   • Trust Management: Only trust devices you recognize
   • Trust Levels: Set Limited, Standard, or High trust levels
   • Auto-Trust Patterns: Set rules for automatic device approval
   • Certificate System: Each device gets unique security certificate

3. 📊 Monitoring

   • Real-time Status: See device connectivity in real-time
   • Connection History: Track device connection counts
   • Transfer Logs: Complete history of all file transfers
   • Security Events: Monitor trust changes and security events

⌨️ Keyboard Shortcuts

Shortcut	Action	Description
Ctrl+O	Select Files	Open file selection dialog
Ctrl+S	Scan Network	Start network device discovery
Ctrl+R	Start Receiver	Begin listening for incoming files
Ctrl+T	Stop Receiver	Stop file service
Ctrl+D	Download Folder	Open downloads directory
F5	Refresh	Refresh device list
F1	Help	Show help information
Escape	Cancel	Cancel current operation

🔧 Advanced Configuration

🎯 Auto-Trust Patterns

Set up rules to automatically trust specific devices:

.*-PC$          # Trusts devices ending with "-PC"
.*-LAPTOP$      # Trusts laptop devices  
OFFICE-.*       # Trusts devices starting with "OFFICE-"
DEV-.*          # Trusts development machines
[A-Z]{2,}-\d+   # Trusts pattern like "WS-01", "SRV-02"

🔐 Trust Levels

• 🔴 Limited: Basic transfers, lower priority
• 🔵 Standard: Normal transfers, standard priority
• 🟢 High: Maximum trust, highest priority, auto-accept

📊 Network Analysis

• Device Categories: Routers, Workstations, Servers, Mobile devices
• Service Detection: HTTP, HTTPS, SSH, SMB, RDP services
• Connection Methods: Ping responsive, Port/ARP detection, File service
• Performance Metrics: Scan time, success rate, device count

⚙️ Configuration Options (config.json)

{
  "app_settings": {
    "app_name": "Secure File Transfer",
    "version": "3.4.01c34",
    "port": 12345,
    "max_file_size_gb": 2,
    "scan_timeout": 30,
    "encryption_enabled": true,
    "auto_accept_trusted": true
  },
  "security_settings": {
    "eset_integration": true,
    "require_device_trust": true,
    "verify_file_integrity": true,
    "encryption_algorithm": "Fernet"
  },
  "network_settings": {
    "discovery_methods": ["ping", "arp", "port_scan", "netbios"],
    "dns_timeout": 0.5,
    "netbios_timeout": 0.5,
    "port_scan_timeout": 0.15
  }
}

🆘 Troubleshooting

🔍 Network Discovery Issues

❌ "No devices found" or "Only 1-2 devices"

• ✅ Check network: Ensure you're on the same subnet (WiFi/Ethernet)
• ✅ Firewall: Temporarily disable Windows Firewall to test
• ✅ Network range: Application auto-detects 10.0.0.x, 192.168.x.x ranges
• ✅ Router settings: Some routers block device discovery
• ✅ Wait longer: Network scan takes 10-30 seconds for completion

❌ "My PC doesn't show as trusted" (Fresh Install)

• ✅ This is CORRECT security behavior: Fresh installs have zero trusted devices
• ✅ Expected workflow:
  1. Download/install application → No trusted devices (secure)
  2. Run application and click "🔍 Scan Network"
  3. Your PC appears as "Untrusted" (this is normal!)
  4. Click "✅ Trust" next to your PC to approve it
  5. Your PC now shows as trusted and ready for transfers
• ✅ Why this happens: Zero-trust security model prevents auto-trust
• ✅ One-time setup: You only need to trust your PC once

❌ "Devices show as 'Untrusted'"

• ✅ This is normal: All devices start untrusted for security
• ✅ Manual trust: Click "✅ Trust" on devices you recognize
• ✅ Install on other PCs: CRITICAL - Install the application on ALL devices you want to transfer files between
• ✅ Start receiver: Target devices need "Start Receiver" running to be "Available"

❌ "Can't send files to other devices"

• ✅ Install app everywhere: Other devices must have this application installed and running
• ✅ Mutual trust required: Both devices must trust each other (Device A trusts B, Device B trusts A)
• ✅ Receiver must be running: Target device must click "🟢 Start Receiver"
• ✅ Same network: All devices must be on the same WiFi/network

❌ "Generic device names like 'Workstation-114'"

• ✅ DNS issues: Some networks don't allow reverse DNS lookup
• ✅ NetBIOS disabled: Windows may have NetBIOS over TCP/IP disabled
• ✅ Still functional: Generic names don't affect file transfer functionality
• ✅ Network admin: Contact IT if in corporate environment

🔧 File Transfer Issues

❌ "Transfer failed" or "Connection refused"

• ✅ Receiver running: Target device must have "Start Receiver" active
• ✅ Trust both ways: Both devices must trust each other
• ✅ Port 12345: Ensure port isn't blocked by firewall/antivirus
• ✅ Disk space: Check available space on receiving device
• ✅ File size: Ensure file doesn't exceed 2GB limit (or configured limit)

❌ "File too large" error

• ✅ Check config.json: Look at "max_file_size_gb" setting
• ✅ Increase limit: Change value from 2 to higher number (e.g., 5 for 5GB)
• ✅ Restart app: Configuration changes require restart
• ✅ Split files: Consider splitting very large files

❌ "Security service not detected"

• ✅ Not critical: Application works without antivirus detection
• ✅ Windows Defender: Always available as fallback
• ✅ Antivirus running: Ensure your security software is active
• ✅ Silent mode: Check if antivirus is in gaming/silent mode

🔧 Performance Optimization

🚀 Speed up network discovery:

• Use wired Ethernet connection instead of WiFi
• Ensure good signal strength for WiFi connections
• Close unnecessary network applications
• Restart router if discovery is very slow

🚀 Speed up file transfers:

• Use wired connections for both devices
• Close bandwidth-intensive applications
• Transfer during off-peak network hours
• Consider file compression for text/document files

🚀 Reduce resource usage:

• Disable auto-scan when not needed
• Close other Python applications
• Ensure sufficient RAM available
• Use SSD storage for better I/O performance

🐛 Getting Help

1. 📋 Check Logs: Look at transfer log and debug output in console
2. 🔧 Reset Settings: Use "Reset Application" in Tools menu
3. 📊 System Info: Use "Report Bug" to generate diagnostic information
4. 🧪 Run Tests: Execute python test_all_features.py to verify functionality
5. ✅ Verification: Run python final_verification.py for full system check

🔒 Security & Privacy

🛡️ Security Model

• Zero-Trust Architecture: No device trusted by default
• Fernet Encryption: All file transfers use industry-standard encryption
• Local Network Only: No internet connection required or used
• Certificate-Based Auth: Unique certificates for each trusted device
• Input Validation: Protection against path traversal and injection attacks

🔐 Privacy Protection

• No Data Collection: All information stays on your local network
• No Cloud Storage: Files never leave your local network
• Trusted Devices Only: You control exactly who can send/receive
• Automatic Cleanup: Temporary files removed after transfer
• Audit Trail: Complete logs of all transfer activity

🚨 Security Best Practices

• Review Trust List: Regularly check trusted devices
• Strong Device Names: Use descriptive, unique device names
• Monitor Transfers: Watch logs for unexpected activity
• Update Software: Keep antivirus and OS updated
• Network Security: Use WPA3 WiFi encryption
• Physical Security: Secure devices running the application

🎯 Use Cases

🏠 Home Network

• Transfer photos/videos between family computers
• Share documents between work laptop and personal desktop
• Move files to/from media center or NAS
• Backup important files to multiple devices

🏢 Small Office

• Secure document sharing between workstations
• Transfer files to presentation/meeting room computers
• Share resources between departments
• Backup files to server or storage devices

💻 Development Team

• Share code, builds, and assets securely
• Transfer large development files
• Distribute software to testing machines
• Backup project files across team devices

🎮 Gaming/Media

• Transfer game saves between computers
• Share media files, screenshots, recordings
• Move large game installations
• Backup gaming profiles and configurations

📈 What's Coming Next

🔮 Future Enhancements

• Mobile Apps: iOS and Android companion apps
• Cloud Integration: Optional secure cloud storage bridges
• Advanced Encryption: Additional encryption algorithms
• Group Management: Manage device groups and permissions
• Bandwidth Controls: QoS and transfer rate limiting
• Remote Access: Secure VPN-like connectivity

🤝 Contributing

• Bug Reports: Use built-in "Report Bug" feature
• Feature Requests: Use "Request Feature" functionality
• Testing: Help test new features and report issues
• Documentation: Suggest improvements to this guide
• Security: Report security issues responsibly

📝 About

🎯 Mission

To provide enterprise-grade secure file transfer capabilities in an easy-to-use application suitable for home users, small businesses, and development teams. Emphasizing security, privacy, and user experience without complexity.

🔧 Technical Excellence

• Python-Based: Cross-platform compatibility and reliability
• Modern UI: CustomTkinter for professional appearance
• Multi-Threading: Responsive interface during network operations
• Robust Error Handling: Graceful handling of network and file system issues
• Comprehensive Testing: Extensive test suite ensures reliability
• Zero Dependencies: Minimal external dependencies for security

🌟 Key Advantages

• User-Friendly: Intuitive interface with helpful tooltips and guidance
• Secure by Default: Zero-trust security model with encryption
• Universal Compatibility: Supports all file types and sizes
• Network Intelligent: Smart device discovery and classification
• Highly Configurable: Extensive customization options
• Professional Grade: Enterprise security features in simple package

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🎉 Ready to Get Started?

🚀 Quick Start (2 Minutes)

1. Install Python (if not already installed)
2. Download application files from GitHub
3. Install dependencies:

   pip install customtkinter cryptography psutil

4. Run application:

   python launchers/launcher.py

5. Scan network and start transferring files securely!

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🔐 Secure File Transfer v3.4.01c34 - Professional file sharing with intelligent network discovery, enterprise security, and zero-trust architecture.

Making secure file transfers simple, intelligent, and professional for everyone.